The main characteristic of the Creator's Pet is that the writers' focus on him is detrimental to the show. It's not that the parts featuring this character necessarily suck more than the rest, but that so much effort is being directed to him that it detracts from the quality of the series as a whole. It's as if the writers think that there's nothing more important than browbeating the viewers into falling in love with this one character. And it never works. In fact, shilling a character excessively can cause other characters to be drawn into the hatred.

Keep in mind that this isn't "The Scrappywith a big role", nor is it the Canon Sue, although there's a lot of overlap in both cases. The Creator's Pet is a combination of being: